/* vi: set sw=4 ts=4: */ /* * Sysctl 1.01 - A utility to read and manipulate the sysctl parameters * * Copyright 1999 George Staikos * * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. * * Changelog: * v1.01: * - added -p <preload> to preload values from a file * v1.01.1 * - busybox applet aware by <solar@gentoo.org> * */ #include "libbb.h" /* * Function Prototypes */ static int sysctl_read_setting(const char *setting, int output); static int sysctl_write_setting(const char *setting, int output); static int sysctl_preload_file(const char *filename, int output); static int sysctl_display_all(const char *path, int output, int show_table); /* * Globals... */ static const char ETC_SYSCTL_CONF[] ALIGN1 = "/etc/sysctl.conf"; static const char PROC_SYS[] ALIGN1 = "/proc/sys/"; enum { strlen_PROC_SYS = sizeof(PROC_SYS) - 1 }; /* error messages */ static const char ERR_UNKNOWN_PARAMETER[] ALIGN1 = "error: unknown parameter '%s'"; static const char ERR_MALFORMED_SETTING[] ALIGN1 = "error: malformed setting '%s'"; static const char ERR_NO_EQUALS[] ALIGN1 = "error: '%s' must be of the form name=value"; static const char ERR_INVALID_KEY[] ALIGN1 = "error: '%s' is an unknown key"; static const char ERR_UNKNOWN_WRITING[] ALIGN1 = "error setting key '%s'"; static const char ERR_UNKNOWN_READING[] ALIGN1 = "error reading key '%s'"; static const char ERR_PERMISSION_DENIED[] ALIGN1 = "error: permission denied on key '%s'"; static const char ERR_PRELOAD_FILE[] ALIGN1 = "error: cannot open preload file '%s'"; static const char WARN_BAD_LINE[] ALIGN1 = "warning: %s(%d): invalid syntax, continuing"; static void dwrite_str(int fd, const char *buf) { write(fd, buf, strlen(buf)); } /* * sysctl_main()... */ int sysctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int sysctl_main(int argc, char **argv) { int retval = 0; int output = 1; int write_mode = 0; int switches_allowed = 1; if (argc < 2) bb_show_usage(); argv++; for (; *argv /*&& **argv*/; argv++) { if (switches_allowed && **argv == '-') { /* we have a switch */ switch ((*argv)[1]) { case 'n': output = 0; break; case 'w': write_mode = 1; switches_allowed = 0; break; case 'p': argv++; return sysctl_preload_file(((*argv /*&& **argv*/) ? *argv : ETC_SYSCTL_CONF), output); case 'a': case 'A': return sysctl_display_all(PROC_SYS, output, ((*argv)[1] == 'A')); default: bb_error_msg(ERR_UNKNOWN_PARAMETER, *argv); /* fall through */ //case 'h': //case '?': bb_show_usage(); } } else { switches_allowed = 0; if (write_mode) retval |= sysctl_write_setting(*argv, output); else sysctl_read_setting(*argv, output); } } return retval; } /* end sysctl_main() */ /* * sysctl_preload_file * preload the sysctl's from a conf file * - we parse the file and then reform it (strip out whitespace) */ #define PRELOAD_BUF 256 static int sysctl_preload_file(const char *filename, int output) { int lineno; char oneline[PRELOAD_BUF]; char buffer[PRELOAD_BUF]; char *name, *value; FILE *fp; fp = fopen(filename, "r"); if (fp == NULL) { bb_error_msg_and_die(ERR_PRELOAD_FILE, filename); } lineno = 0; while (fgets(oneline, sizeof(oneline) - 1, fp)) { lineno++; trim(oneline); if (oneline[0] == '#' || oneline[0] == ';') continue; if (!oneline[0] || !oneline[1]) continue; name = strtok(oneline, "="); if (!name) { bb_error_msg(WARN_BAD_LINE, filename, lineno); continue; } trim(name); if (!*name) { bb_error_msg(WARN_BAD_LINE, filename, lineno); continue; } value = strtok(NULL, "\n\r"); if (!value) { bb_error_msg(WARN_BAD_LINE, filename, lineno); continue; } while (*value == ' ' || *value == '\t') value++; if (!*value) { bb_error_msg(WARN_BAD_LINE, filename, lineno); continue; } /* safe because sizeof(oneline) == sizeof(buffer) */ sprintf(buffer, "%s=%s", name, value); sysctl_write_setting(buffer, output); } fclose(fp); return 0; } /* end sysctl_preload_file() */ /* * Write a single sysctl setting */ static int sysctl_write_setting(const char *setting, int output) { int retval = 0; const char *name; const char *value; const char *equals; char *tmpname, *outname, *cptr; int fd = -1; name = setting; equals = strchr(setting, '='); if (!equals) { bb_error_msg(ERR_NO_EQUALS, setting); return -1; } value = equals + 1; /* point to the value in name=value */ if (name == equals || !*value) { bb_error_msg(ERR_MALFORMED_SETTING, setting); return -2; } tmpname = xasprintf("%s%.*s", PROC_SYS, (int)(equals - name), name); outname = xstrdup(tmpname + strlen_PROC_SYS); while ((cptr = strchr(tmpname, '.')) != NULL) *cptr = '/'; while ((cptr = strchr(outname, '/')) != NULL) *cptr = '.'; fd = open(tmpname, O_WRONLY | O_CREAT | O_TRUNC, 0666); if (fd < 0) { switch (errno) { case ENOENT: bb_error_msg(ERR_INVALID_KEY, outname); break; case EACCES: bb_perror_msg(ERR_PERMISSION_DENIED, outname); break; default: bb_perror_msg(ERR_UNKNOWN_WRITING, outname); break; } retval = -1; } else { dwrite_str(fd, value); close(fd); if (output) { dwrite_str(STDOUT_FILENO, outname); dwrite_str(STDOUT_FILENO, " = "); } dwrite_str(STDOUT_FILENO, value); dwrite_str(STDOUT_FILENO, "\n"); } free(tmpname); free(outname); return retval; } /* end sysctl_write_setting() */ /* * Read a sysctl setting */ static int sysctl_read_setting(const char *setting, int output) { int retval = 0; char *tmpname, *outname, *cptr; char inbuf[1025]; const char *name; FILE *fp; if (!*setting) bb_error_msg(ERR_INVALID_KEY, setting); name = setting; tmpname = concat_path_file(PROC_SYS, name); outname = xstrdup(tmpname + strlen_PROC_SYS); while ((cptr = strchr(tmpname, '.')) != NULL) *cptr = '/'; while ((cptr = strchr(outname, '/')) != NULL) *cptr = '.'; fp = fopen(tmpname, "r"); if (fp == NULL) { switch (errno) { case ENOENT: bb_error_msg(ERR_INVALID_KEY, outname); break; case EACCES: bb_error_msg(ERR_PERMISSION_DENIED, outname); break; default: bb_perror_msg(ERR_UNKNOWN_READING, outname); break; } retval = -1; } else { while (fgets(inbuf, sizeof(inbuf) - 1, fp)) { if (output) { dwrite_str(STDOUT_FILENO, outname); dwrite_str(STDOUT_FILENO, " = "); } dwrite_str(STDOUT_FILENO, inbuf); } fclose(fp); } free(tmpname); free(outname); return retval; } /* end sysctl_read_setting() */ /* * Display all the sysctl settings */ static int sysctl_display_all(const char *path, int output, int show_table) { int retval = 0; DIR *dp; struct dirent *de; char *tmpdir; struct stat ts; dp = opendir(path); if (!dp) { return -1; } while ((de = readdir(dp)) != NULL) { tmpdir = concat_subpath_file(path, de->d_name); if (tmpdir == NULL) continue; if (stat(tmpdir, &ts) != 0) { bb_perror_msg(tmpdir); } else if (S_ISDIR(ts.st_mode)) { sysctl_display_all(tmpdir, output, show_table); } else { retval |= sysctl_read_setting(tmpdir + strlen_PROC_SYS, output); } free(tmpdir); } /* end while */ closedir(dp); return retval; } /* end sysctl_display_all() */